Membrane bioreactors as an alternative to conventional waste water treatment processes

In the field of biotechnology, membranes have been incorporated into bioreactors in a number of established fields. These include continuous biotransformation using enzymes retained behind or immobilised onto the membrane, continuous fermentation, where the membrane is employed to provide cell recycle and therefore a high intensity process, and in mammalian cell culture, where the membrane provides both a physical support for the cells, and a means of low-shear aeration. The use of membrane bioreactors in waste water treatment is now emerging as an attractive technology with considerable advantages over conventional treatment methods. This paper reviews the current application of membrane bioreactors in industrial, domestic and food processing waste treatment, and also drinking water treatment. The paper concludes by speculating on potential applications of the technology in the future and the improvements which will be necessary in order to realise them.